It's neither. It's called the Sea Shadow and as far as I know it's the only one running. It's was the Navy's test bed for stealth ship technology. It works kind of like a catamaran. It is multi-hulled, there are two smaller hulls underneath the water, which is supposed to make this baby faster and also not leave such a large wake behind it. I don't know that it is even armed at all at this point. Some of the navy guys on here may be able to give you a more in depth review on it.